Animal rights activists have launched a fresh wave of attacks, targeting a
senior pharmaceutical executive and an Oxford college.

The Animal Liberation Front (ALF) claimed responsibility yesterday for a device left outside the home of Paul Blackburn, the corporate controller of Britain's biggest pharmaceutical company, GlaxoSmithKline (GSK).

A device containing fuel had been left on Mr Blackburn's porch, a GSK spokesman said. It is understood that Mr Blackburn was abroad at the time, but his wife and daughter were at the house. The device caused only minor damage.

A posting on the ALF website Biteback said it was responsible for the attack, which had been carried out because GSK was a customer of the animal testing group Huntingdon Life Sciences.

"GSK, we realise that this may not be enough to make you stop using HLS but this is just the beginning," the post said. "We have identified and tracked down many of your senior executives and also junior staff, as well as those from other HLS customers. Drop HLS or you will face the consequences. For all the animals inside HLS, we will be back."

Anti-vivisectionists also attacked an Oxford college sports pavilion as a protest against a primate laboratory being built by the university. Police were called to a sports pavilion on the Abingdon Road, owned by Corpus Christi College, on Saturday.

Sources close to the university said the device was disabled and little damage was done. However, the ALF claimed that it had spent the past 15 months researching the university and threatened to destroy all of its property if it did not stop building the facility to house animals for research on South Park Road.

"We know every weakness you have," the ALF website said. "You have people within your ranks acting against you. You cannot build the South Park lab without incurring massive losses. We are stronger than you, we have more resolve than you and we never give up!

"If we have to destroy every bit of property you own we will, in order to stop you inflicting your profit-driven cruelties on defenceless creatures. You cannot stop us, we are free to attack you at will, whenever and wherever."

The action follows an arson attack on Oxford University in July, which destroyed a boathouse belonging to Hertford College. The ALF claimed responsibility. Construction has already been halted on the primate laboratory after the contractor, Montpellier Group, withdrew after shareholders were threatened. The university has said it is committed to building the laboratory.

Pharmaceutical insiders have said they fear a campaign of renewed violence from activists after a firebomb was placed at the home of a senior Canaccord broker.

The Association of the British Pharmaceutical Industry said last month that there had been a "worrying increase in the severity" of some of the animal rights attacks in the past year.

"While the reduction in the number of incidents is welcome, it is disturbing that in some cases we are seeing more aggressive attacks taking place," said a spokesman. "Someone is going to get hurt or killed if this goes on."